I'm working with OpenGL ES 2.0 and have some questions when it comes to glBufferSubData
1. Does this command lock down my VBO, even when only using a limited section of the buffer? I heard that if I were to draw half of my buffer and then write to the other half of the buffer. The GPU will stall until the draw command is finished. Is this true?
2. When orphaning should I be orphaning every frame? I feel like I should only orphan when my buffer is full, but if the above is true I feel like it is a little counter productive to orphan. Since I still am getting locked down / stalling the gpu from the glBufferSubData call